PURPOSE: To prevent system resources from being wasted by a holding state until executing the return of a real terminal and to facilitate communication between sub systems in the case of emergency concerning the sub system calling system at an information processing system to exchange the real terminal through a communication control program.

CONSTITUTION: When passing (applying) a real terminal 1, an application program ending means 7-1 designates the handling of an application program 10-1 operated at the sub system of the pass source, and an inter-sub system information communication means 3-1 executes transmission/reception between session control programs 6-1 and 6-n each other.